Opened 8 years ago

Last modified 13 months ago

#799 new enhancement/feature request

Bearing should keep current value for some time after GPS signal lost

Reported by: benja1972 -2- Owned by: KaZeR
Priority: minor Milestone: version 0.5.2
Component: core Version: git master
Severity: Keywords: gps, map, bearing
Cc: michael@…

Description

Bearing should keep current value for some time (time delay) after GPS signal lost. In fact GPS unit can still produce information on position and speed but lost bearing value. It is happed when your device doesn't have compas and bearing is going from GPS chip. This is my case on Android device with weak GPS chip. Thus when Navit not getting info on bearing it put it to zero. It lead to jumping the map view very frequently wuth weak signal from GPS. The situation is ike this:

GPS bearing: 132 130 129 NaN 131 NaN NaN 130 128 NaN

Navit bearing: 132 130 129 0 131 0 0 130 128 0

Intended bearing: 132 130 129 129 131 131 131 130 128 128

Navit should keep previous values some seconds and there is no new info from GPS jumps to zero (or fade to zero)

Change History (6)

comment:1 Changed 8 years ago by alexwien

Heading/Course? becomes invalid when a vehicle stops. What is missing in Navit, on my oppinion is a so called "standstill filter", which freezes postion (lat/lon) and heading while the vehicle is standing. Sirf calls this "StaticNavigation?" filter, you can configure a GPS receiver to enable this mode. Ublox receivers have another name for that feature, but you can enable that too.

In general an invalid heading/course (synonyms) (NaN, NULL, "") should not be set to 0; internally you might use a special value outside of the valid range, like "-1", and hide the compass and freeze navigation and movement of the map; Same applies for latitude/ longitude coordinates: if invalid or not existing, they should never get the valid value 0 (but this is less critical, than the heading = 0);

In my GPS applications, I implemented a standstill filter which freezes position and course while speed is too low. This is better than to set the GPS in standstill Filter mode.

If you want to spend as less effort as possible for such a feature, then simply rotate the map only when the speed of the GPS fix is > 5km/h. (Simple and effective)

comment:2 Changed 8 years ago by korrosa

Even better - make the speed at which Navit assumes movement configurable. I've turned off the StaticNavigation? filter on my SiRF device because I've been using Navit whilst walking: having a configurable setting would allow me to change vehicle profiles (if that's where the attribute can be specified) depending on if I'm walking, cycling or driving...

comment:3 Changed 7 years ago by mvglasow (2)

For the "bearing when standing still" issue, see #920

comment:4 Changed 7 years ago by mvglasow (2)

  • Cc michael@… added

comment:5 Changed 5 years ago by usul

  • Keywords gps map bearing added
  • Milestone set to version 0.5.1

So nothing seems to be done to address this issue already?

As this "jumping" in view angle is very anoying, IMHO we need to fix it as soon as possible.

comment:6 Changed 13 months ago by http://wiki.navit-project.org/index.php/user:jkoan

  • Milestone changed from version 0.5.1 to version 0.5.2

This ticket was pushed back in order to bring 0.5.1 out soon.

Note: See TracTickets for help on using tickets.